# CVE-2026-119233: CVE-2026-119233

Status: published. Published: 2026-11-11. Updated: 2026-11-11.

proxygen's HTTP/3 codec buffered an incomplete non-DATA frame, such as a control-stream frame, a frame of an unknown or reserved type, or a HEADERS frame, until its entire declared length had arrived, without limiting that length, and re-scanned all buffered data each time more bytes arrived. A remote, unauthenticated HTTP/3 peer could declare a very large frame and deliver it slowly, causing unbounded memory growth and CPU usage that grows quadratically with the number of fragments, leading to denial of service. This issue affects proxygen versions prior to v2026.11.09.00.

## Remediation

No remediation reported in collected sources

## Affected products and versions

- Facebook / proxygen: ≥ v0.0.0.0; < v2026.11.09.00 (affected, semver). Source: CNA: Meta

## Severity and prioritization

- CISA KEV: No listing in collected sources

- EPSS: Not available

- SSVC: Not available

- Weaknesses: CWE-770

## Exploit evidence

No exploit evidence in collected sources. This is not proof of no exploitation.

## References

- https://www.facebook.com/security/advisories/cve-2026-119233 (CNA: Meta; x_refsource_CONFIRM)

- https://github.com/meta/proxygen/commit/daf245bba7fe1304b9491403fe56f91153299781 (CNA: Meta; x_refsource_MISC)

- https://github.com/meta/proxygen/commit/daf245bba7fe1304b9491403fe56f91153299781 (cve-assign@fb.com)

- https://www.facebook.com/security/advisories/cve-2026-119233 (cve-assign@fb.com)

## Provenance

- CNA: Meta: https://www.cve.org/CVERecord?id=CVE-2026-119233; retrieved 2026-11-11; source updated 2026-11-11

- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-119233; retrieved 2026-11-11; source updated 2026-11-11

Revision: be31821ee86fe07cbca1f33eb151a398164994f5ab7adbef27239683024cb439

Canonical: https://y2.dev/cve/CVE-2026-119233

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